<?php

function combine($strokes, $maxStroke) {
	if (!$strokes)
		return new ArrayIterator(array(array()));
	if (!$maxStroke || $strokes < 0)
		return new EmptyIterator();
	for ($i = $strokes / $maxStroke; $i > 0; ++$i) {
		// TODO think of Generator routing in PHP
	}
}